This invention relates to apparatus for use in filling a fuel tank of a boat with liquid fuel, and more particularly to an arrangement for providing a warning signal after the tank is full and before fuel erupts from the tank vent, so that the filling of the tank can be halted prior to the escape of any fuel.
Fuel tanks for boats usually have a generally vertical filling pipe and a generally vertical vent stack, the top of the vent stack being at a lower elevation than the top of the filling pipe, and usually exiting through the hull of the boat. The vent stack has a relatively small inside diameter, typically on the order of 1/2 inch to 9/16 inch.
As a result of the small diameter of the vent pipe, when the fuel tank (which fills relatively slowly) has filled to capacity, fuel rises very rapidly in the vent stack and continues to do so until the flow of fuel into the filling pipe is halted.
At present, when a fuel tank of a boat is being filled, the person doing so watches the vent stack and stops filling the tank when fuel starts to spurt out of the top of the stack. This results in the fuel which comes out of the stack spilling onto the boat or into the water, presenting a safety and/or environmental hazard.
In U.S. Pat. No. 4,802,514 to Morse, excess fuel which spills out of the vent stack is caught by a receptacle temporarily secured to the hull by suction cups. The receptacle must be installed before, and removed and emptied after each refueling operation, a time consuming and tedious process.
U.S. Pat. No. 4,854,469 to Hargest provides a baffled housing coupled to the top of the vent stack to serve as a small reservoir which contains fuel coming out of the stack for a short time which is long enough to allow the filling of the tank to be halted. The housing has a transparent wall through which one can watch for the spurting of fuel from the top of the vent stack and thus stop filling the tank before the reservoir fills and the excess fuel comes out of the top of the vent stack.
The arrangement of Hargest, however, suffers from several drawbacks. Since the first indication of the tank having been filled is the visual observation of the spurting of fuel from the top of the vent stack, the housing must necessarily be positioned at the top of the stack, which precludes early detection of the full condition of the fuel tank. Further, constant cleaning of the inner and outer surfaces of the transparent wall is necessary to prevent the view of the top of the vent stack from being obscured. The housing of Hargest must be positioned where it can be readily seen, an esthetically undesirable situation and one which does not allow for positioning of the housing where it will make the most efficient use of available space. In addition, the arrangement of Hargest is incapable of providing a remote audible and/or visual warning signal.
While various float and sight glass mechanisms are known in the art for monitoring the level of fuel in a tank, these are not sufficiently accurate and/or too slow to respond, for the purpose of determining when the fuel tank of a boat is full, in sufficient time so that the filling of the tank can be halted before fuel spills from the vent stack into the environment. See, for example, U.S. Pat. Nos. 1,316,167 to Lecrone; 2,947,330 to Savage; 3,684,127 to Kruse; 4,083,387 to Stieber et al.; and 4,815,436 to Sasaki et al.
Accordingly, an object of the present invention is to provide an improved apparatus for use in filling a fuel tank of a boat with liquid fuel, which is capable of providing a warning signal when the tank is filled to capacity and before fuel spills out of the vent stack into the environment.
Another object of the invention is to provide an improved apparatus for facilitating the filling of a fuel tank of a boat without spillage of fuel out of the top of the vent stack, which apparatus can be simply and easily retrofitted to existing tank installations.